In Photoshop CC, when I attempt to use the Quick Mask (create a selection and press 'Q' key), part of the image turns the mask color and then the application freezes. This happens every time. I've attached a sample of a frozen screen. You can see the very top of my selection in upper-right of the unmasked portion of the image.

Hi,
I have this problem still, exactly as described here, attempting a quick mask makes CC crash. I then had the problem that when trying to restart it would attempt to recover the document and... crash again effectively locking me out.

Strangely there is an installation under Program Files called CC (64 bit ) while under Program Files (x86) there is a normal version (I presume 32bit) I opened this and it work and corrected the 'recovering files' problem.

For info I have a Radion R7 chip-set and clearly the latest drivers have not fixed the issue as suggested by your links above (the beta one links to an access denied page)

So now I need to know how to set the GPU mode on the 64bit version as mentioned above? Please can you let me know where this is done.

This has been happening to me as well for the last month or so as well. And, it happens both when trying to pull up the Quick Mask (Q) and when using the Layer Mask Rubylith (\), which I do more often.

As it turns out, the issue is in fact the graphics processor. Changing the drawing mode to "Normal" did the trick.

But... I am confused as to why this would all of a sudden be a problem. I have been using OpenGL on my Window 7 64-bit PC for at least a couple years now and had no issue with I first upgraded to Photoshop CC 64-bit mid-year last year. My video drivers and Photoshop are up to date.